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Shortwave vs Stalwart

A side-by-side editorial comparison of Shortwave and Stalwart — release velocity, themes, recent moves, and the top alternatives to consider.

Shortwave vs Stalwart: at a glance

FeatureShortwaveStalwart
SectorCommsComms
Velocity score0.05.0
Sparks · 30d00
Top themesai-email, agentic-workflows, mcp, automationmail-server, jmap, imap, rfc-compliance
Last editorial update1mo ago20h ago
WebsiteVisit →Visit →

What is Shortwave?

Shortwave keeps folding autonomy into the inbox, one AI action at a time.

Shortwave has moved decisively from an AI-assisted email client to an inbox that acts on the user's behalf. The assistant reads, drafts, organizes, and — via the Tasklet integration — triggers automated workflows across thousands of apps, with its work surfaced inside Shortwave rather than buried in Gmail. Every release since late 2024 has pushed more of the email workflow out of the user's hands and into the model's.

Read the full Shortwave trajectory →

What is Stalwart?

Stalwart is chasing mail RFCs and its own storage layer at the same time

Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.

Read the full Stalwart trajectory →

Shortwave vs Stalwart: editorial side-by-side

S0.0

Shortwave keeps folding autonomy into the inbox, one AI action at a time.

◆ Current state

Shortwave has moved decisively from an AI-assisted email client to an inbox that acts on the user's behalf. The assistant reads, drafts, organizes, and — via the Tasklet integration — triggers automated workflows across thousands of apps, with its work surfaced inside Shortwave rather than buried in Gmail. Every release since late 2024 has pushed more of the email workflow out of the user's hands and into the model's.

◆ Where it's heading

The direction is a steadily widening action surface: MCP connectors to external tools, AI Memories, voice, and now trigger-based automation all frame email as an agent runtime rather than a reading pane. Model choices track the frontier closely — Claude 3.7 to Sonnet 4 to the 4.6 family — keeping capability tied to whatever the best available model can do. The team ships broadly across web, desktop, iOS, and Android each cycle.

◆ Prediction

The next moves most likely deepen autonomous execution — more trigger types and tighter loops where the assistant acts with less confirmation — rather than adding new surface features.

S5.0

Stalwart is chasing mail RFCs and its own storage layer at the same time

◆ Current state

Stalwart ships roughly weekly, and the releases divide cleanly between standards implementation and correctness work. v0.16.18 turns toward resource control — bounds on decompressed inbound DMARC and TLS report size, a cap on RocksDB block-cache memory, column families tuned per access pattern, and a queue scheduler that stops rescanning from the earliest pending event. The preceding releases added IMAP UIDONLY, UIDBATCHES and MESSAGELIMIT, plus JMAP email push and VAPID.

◆ Where it's heading

Two threads run through every release. One is RFC coverage across IMAP, JMAP, CalDAV and WebDAV, implemented close to the specification including drafts. The other is a long tail of protocol-conformance fixes, many of them cases where JMAP and IMAP disagreed about the same state. The newest release adds a third: memory and scheduling limits, which is what a server codebase starts doing when deployments get large enough for defaults to hurt.

◆ Prediction

Expect continued RFC additions across the JMAP and IMAP surfaces, with more of the storage-tuning work that v0.16.18 started as RocksDB deployments scale.

Alternatives to Shortwave and Stalwart

Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Shortwave or Stalwart.

See all Shortwave alternatives → · See all Stalwart alternatives →

Recent activity from Shortwave and Stalwart

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 1d agoStalwartResource limits arrive for inbound reports and RocksDB caches
  2. 8d agoStalwartIMAP gains UIDONLY, UIDBATCHES and message-limit extensions
  3. 16d agoStalwartJMAP delivery push arrives; strict relays stop rejecting calendar mail
  4. 23d agoStalwartFix-only release: JMAP semantics and a credential escalation
  5. 29d agoStalwartVAPID lands for JMAP Web Push
  6. 1mo agoStalwartFreeBSD support, plus OAuth scopes for IMAP, SMTP and Sieve
  7. 5mo agoShortwaveUpgraded to Claude Sonnet & Opus 4.6
  8. 7mo agoShortwaveFully automate your email with Tasklet 🔗
  9. 11mo agoShortwaveEnhanced AI performance & collaboration
  10. 1y agoShortwaveIntegrate the AI with all your apps 🔌
  11. 1y agoShortwaveTalk to your inbox 🎙️
  12. 1y agoShortwaveOrganize your inbox with AI ✨

Frequently asked questions

What is the difference between Shortwave and Stalwart?

They serve adjacent needs but don't currently overlap on shipped themes. Stalwart is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is Shortwave better than Stalwart?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Stalwart is currently shipping more aggressively (velocity 5.0 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.

What are the best alternatives to Shortwave?

Top Shortwave alternatives in Comms are ranked by recent ship velocity. Browse the "Shortwave alternatives" section above for the current picks, or visit /alternatives/shortwave for the full list with editorial commentary on each.

What are the best alternatives to Stalwart?

Top Stalwart alternatives in Comms are ranked by recent ship velocity. Browse the "Stalwart alternatives" section above for the current picks, or visit /alternatives/stalwart for the full list with editorial commentary on each.